This invention relates generally to the processing of thermoplastic films and laminates, and more particularly to an apparatus and method for pleating or folding such films or laminates.
Thermoplastic films and laminates have a wide variety of uses, one of which is the use of such films and laminates as a storm window replacement. For retailing purposes, it is desirable that such materials be conveniently packaged in a relatively small display package, to be purchased and then unfolded by the customer at point of use.
One difficulty with this method of marketing such films is the fact that the original dimensions of the film are often much greater than the final dimensions desired for the commercial package. For example, a typical film useful for storm window applications is coextruded and ultimately wound onto a core with a width of 42". It is therefore clear that the film must be folded in such a manner that it can be accommodated in for example a 6" wide package for retail sales.
In the past, this original roll stock film could be center folded by means well known in the art, and then recenterfolded a second time, and perhaps a third time until the final reduced dimensions of the folded film were obtained. This process is costly and time consuming. It would be of great benefit to provide an apparatus and method for folding such roll stock films and laminates to the desired reduced dimension without the need for repetitive sequential center folding steps.
Of interest is U.S. Pat. No. 4,326,664 issued to Benoit et al and disclosing a thermoplastic bag in which pleats are introduced into certain portions of the bag by impressing the bag between matched metal rollers or plates having peaks or truncated peaks with matching recesses.
It is therefore an object of the present invention to provide an apparatus and method for pleating or folding film without the need for sequential center folding operations on the film prior to packaging the film in a final retail package.
It is also an object of the present invention to provide such an apparatus and method where roll stock film may be directly and continuously pleated or folded to the desired reduced width in a single operation.